<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* 
        浮动的本质功能：用来实现并排
        要点：要浮动，都浮动
        父盒子要有足够的宽度，否则会掉下来
        */
        .box{
            width: 600px;
            height: 200px;
            border: 1px solid #000;
        }
        .item{
            width: 200px;
            height: 200px;
            float: left;
        }
        .b1{
            background-color: aqua;
        }
        .b2{
            background-color: red;
        }
        .b3{
            background-color: yellow;
        }
    </style>
</head>
<body>
    <h1>浮动的本质</h1>
    <div class="box">
        <div class="item b1"></div>
        <div class="item b2"></div>
        <div class="item b3"></div>
    </div>
</body>
</html>